163 research outputs found

    Guest Lecture – Foundation Engineering for Gravity Structures in the Northern North Sea

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    During the past 10 years, 15 gravity structures have been installed in the northern North Sea. As new gravity structures are being designed for installation on softer soils and at greater depths, they still pose a great challenge to soil mechanics and foundation engineering. Great improvements have been made during the 10-year period. This applies to soil investigations, in-situ measurements, undisturbed sampling, laboratory testing and design analyses. Compared to structures on land, offshore gravity structures are characterised by large foundation areas, the installation method, and the cyclic wave loading state. The paper reviews investigation methods, site and soil conditions, construction principles, instrumentation and installation. The main emphasis, however, is given to current foundation design practice and experiences from full scale measurements

    Acacia trees on the cultural landscapes of the Red Sea Hills

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    This paper examines interactions between five pastoral nomadic culture groups of the Egyptian and Sudanese Red Sea Hills and the acacia trees Acacia tortilis (Forssk.) Hayne subsp. tortilis and subsp. raddiana growing in their arid environments. A. tortilis is described as a keystone species both ecologically and culturally: the trees play such critical roles in ecosystems and social groups that their removal would greatly impact both systems. Interviews in the field with the Semitic, Arabic-speaking Ma‘aza and Ababda, and the Cushitic, Beja, Bidhaawyeet-speaking Bishaari, Amar Ar and Hadandawa nomads probed the cultural and ecological contexts of acacias in pastoral nomadism, revealing deep insight into traditional ecological knowledge and traditional perceptions and uses of the trees. The paper describes how this knowledge guides pastoral decision-making, with acacias as a particularly critical component of the pastoral livelihood in both normal and stressful circumstances. A. tortilis is the most important reliable vegetation resource for nomads while also providing fuel and other useful products, ecosystem services for people and animals, and increased biodiversity by providing diverse microhabitats and resources for other species. We describe aspects of kinship, territorial organization, spiritual beliefs and tribal law underlying the significance of trees on the cultural landscape. We discuss environmental and economic challenges to human/tree relationships and to pastoral livelihoods. We challenge views of nomads as agents of ecological destruction, and propose maintenance and restoration of traditional pastoralism as viable alternatives in dryland development.publishedVersio

    ACCELERATED LEARNING BERBANTUAN SOFTWARE MAPLE SEBAGAI UPAYA MENINGKATKAN KEMAMPUAN KOMUNIKASI MATEMATIS DAN MINAT BELAJAR SISWA SMA

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    Penelitian ini dilatarbelakangi oleh pentingnya kemampuan komunikasi matematis dan minat belajar. Namun kenyataan di lapangan menunjukkan bahwa kemampuan komunikasi matematisdan minat belajarsiswa masih rendah. Agar permasalahan tersebut dapat diatasi, diperlukan sebuah model pembelajaran yang dapatmeningkatkankemampuan komunikasi matematis dan minat belajarsiswa.Olehkarenaitu, dipilih modelAccelerated Learning Berbantuan Software Maple. Penelitian ini bertujuan untuk menelaahpeningkatan kemampuan komunikasi matematis dan minat belajarsiswa, danmenelaahhubunganantara kemampuan komunikasi dan minat belajar.Penelitianinimerupakanpenelitiankuasieksperimendenganpretest-postest control group design. Populasi pada penelitian ini adalah seluruh siswa kelas X pada salah satu SMA Negeri di Kota Purwokerto. Sampel terdiri dari dua kelas yang dipilih secara purposive sampling.Instrumen yang digunakan berupa tes kemampuan komunikasi matematis dan angket minat belajar, lembar observasi, serta pedoman wawancara. Analisis data dilakukan secara kuantitatif.Analisis data tersebutmenggunakanMann-Whitney U Testdan uji asosiasi Chi Square. Berdasarkan analisis data, ditemukan bahwa: (1)pencapaian kemampuan komunikasi matematis siswa yang memperoleh Accelerated LearningBerbantuanSoftware Maplelebih baik daripada siswa yang memperoleh pembelajaran biasa;(2) peningkatan kemampuan komunikasi matematis siswa yang memperoleh Accelerated LearningBerbantuanSoftware Maplelebih baik daripada siswa yang memperoleh pembelajaran biasa, (3) pencapaian kemampuan minat belajar siswa yang memperoleh Accelerated LearningBerbantuanSoftware Maplelebih baik daripada siswa yang memperoleh pembelajaran biasa; (4) peningkatan kemampuan minat belajar siswa yang memperoleh Accelerated LearningBerbantuanSoftware Maplelebih baik daripada siswa yang memperoleh pembelajaran biasa; dan(5) terdapat asosiasi antara kemampuan komunikasi dan minat belajarsiswadengan kategori rendah. ---------- This research was motivated by the importance of mathematical communication learning interest of students. Mathematical communication ability and learning interest of students is still low. In order that this problemscan be solved, alearning modelthatcan enhancemathematical communication and learning interest ofstudents is required.In this research, Maple-Assisted Accelerated Learning was selected. This studyaims to analyzetheenhancement of mathematical communication learning interest of students, and to analyzetheassociationbetween mathematical communication ability andlearning interest of students. This research was aquasi-experimentalwithpretest-posttest control group design. The population was students at tenth gradein one of senior high schools in Purwokerto, Central Java. The sample consisted oftwoclasses which wasselected bypurposivesampling. This research used fourinstruments: testof mathematicalcommunication ability, learning interestquestionnaire, observation sheets, and interview guide.Data analyzed was done quantitatively. The data were analyzed by usingMann-Whitney U TestandChi Squaren test. Based on the data analyze, it is found that: (1) the achievement of mathematical communication ability of students who receivedthe Maple-Assisted Accelerated Learning is betterthan the achievement of students who receivedconventionallearning;(2) The enhancement of mathematical communication ability of students who receivedthe Maple-Assisted Accelerated Learning is betterthan the enhancement of students who receivedconventionallearning; (3)the achievement oflearning interestability of students who receivedthe Maple-Assisted Accelerated Learning is betterthan the achievement of students who receivedconventionallearning; (4)the enhancement oflearning interestof students who receivedthe Maple-Assisted Accelerated Learning is betterthan the enhancement of students who receivedconventionallearning; and(5) there is anassociation between students’ mathematical communication ability and learning interest of student

    Determination of cyclic soil parameters for offshore foundation design from an existing data base

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    Determination of the soil parameters in the foundation design analyses for offshore and nearshore platforms subjected to cyclic loading from wind and waves requires extensive advanced laboratory testing. The amount of such testing can be reduced by drawing on the experience that has been gained during the design of offshore structures in the past. It is outlined how an existing data base can be used to estimate the soil parameters needed in the foundation design analyses based on conventional parameters, like undrained static shear strength, plasticity index and overconsolidation ratio for clays, and relative density and/or water content, fines content and overconsolidation ratio for sand and silt. The estimated soil parameters can be used in feasibility analyses before site-specific parameters are available and to reduce the amount of site-specific advanced laboratory testing in the final design phase. The application of the data base is demonstrated by examples for clay and for sand with different fines content.publishedVersionPeer reviewe

    Changes in adolescents' intake of sugar-sweetened beverages and sedentary behaviour: Results at 8 month mid-way assessment of the HEIA study - a comprehensive, multi-component school-based randomized trial

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    <p>Abstract</p> <p>Background</p> <p>Inconsistent effects of school-based obesity prevention interventions may be related to how different subgroups receive them. The aim of this study was to evaluate the effect of an intervention program, including fact sheets to parents and classroom components, on intake of sugar-sweetened beverages (SSB) and screen time. Further, to explore whether potential effects and parental involvement varied by adolescents' gender, weight status (WS) and parental educational level.</p> <p>Methods</p> <p>In total, 1465 11-year-olds participated at the pre-test and the 8 month mid-way assessment of the HEIA study. Parents (n = 349) contributed with process evaluation data. Self-reported intake of SSB was collected from the 11-year-olds assessing frequency and amount, while time used on watching TV/DVD and computer/game-use (weekday and weekend day) were assed by frequency measures. Data on awareness of the intervention and dose received were collected from parents. Covariance analyses (ANCOVA) were conducted testing for effects by gender and for moderation by WS and parental education.</p> <p>Results</p> <p>Time spent on TV/DVD (week p = 0.001, weekend p = 0.03) and computer/game-use (week p = 0.004, weekend p <.001), and the intake of SSB during weekend days (p = 0.04), were significantly lower among girls in the intervention group compared to the control group girls after 8 months. Girls' WS did not moderate these findings. However, no significant effects of the intervention were found for boys, but moderation effects were found for WS (week days: TV/DVD, p = 0.03 and computer/games, p = 0.02). There were no moderating effects of parental education for neither boys nor girls with respect to intake of SSB, time used for watching TV/DVD and computer/game-use. Parental awareness of the intervention was significantly higher among the parents of girls, while the parents of boys were more satisfied with the fact sheets.</p> <p>Conclusions</p> <p>The preventive initiatives appeared to change behaviour in girls only. This study suggests that exploration of potential beneficial or negative effects of intervention in subgroups is important. In formative evaluation of obesity prevention studies it seems warranted to include issues related to gender, WS and parental involvement in order to enhance the effectiveness of preventive initiatives.</p

    Changes in meal pattern among Norwegian children from 2001 to 2008

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    OBJECTIVE: The present study aimed to analyse changes in meal pattern among Norwegian children from 2001 to 2008 in general; to analyse associations between meal pattern and gender, parental educational level and number of parents in the household; and to analyse the association between intake of unhealthy snacks, meal pattern and the mentioned variables. DESIGN: Within the Fruits and Vegetables Make the Marks (FVMM) project, two cross-sectional studies were conducted, one in 2001 and one in 2008, where participants from the same schools filled in a questionnaire on meals eaten the previous day. SUBJECTS: Participants were 6th and 7th grade pupils, n 1488 in 2001 and n 1339 in 2008. SETTING: Twenty-seven elementary schools in two Norwegian counties. RESULTS: There were no significant changes in children's meal pattern from 2001 to 2008. For both years more than 90 % of the participants reported that they had breakfast yesterday, while 95 % had lunch, 94 % had dinner and 82 % had supper. More girls than boys reported that they had lunch yesterday (96 % v. 94 %, P = 0·03). More children with higher v. lower educated parents reported that they had breakfast yesterday (93 % v. 88 %, P < 0·001). More children living with two parents v. one parent had breakfast (93 % v. 88 %, P = 0·001) and lunch yesterday (97 % v. 93 %, P < 0·001). CONCLUSIONS: There were no changes in meal pattern from 2001 to 2008 among Norwegian children. Characteristics associated with skipping meals were living in a one-parent family and having lower educated parents

    Mortality, Recruitment and Change of Desert Tree Populations in a Hyper-Arid Environment

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    BACKGROUND: Long-term vegetation changes in hyper-arid areas have long been neglected. Mortality, recruitment and change in populations of the ecologically and culturally important and drought persistent Acacia tortilis and Balanites aegyptiaca are therefore estimated in the Eastern Desert of Egypt, and are related to the primary agents of change, water conditions and human intervention. METHODOLOGY: A change analysis using high-resolution Corona images (1965) in combination with field data (2003) is the basis for recruitment, mortality and change estimates. For assessing the influence of water conditions on patterns in recruitment and survival, different types of generalized linear models are tested. CONCLUSIONS: The overall trend in population size in that part of the Eastern Desert studied here is negative. At some sites this negative trend is alarming, because the reduction in mature trees is substantial (>50%) at the same time as recruitment is nearly absent. At a few sites there is a positive trend and better recruitment. Frequent observations of sprouting in saplings indicate that this is an important mechanism to increase their persistence. It is the establishment itself that seems to be the main challenge in the recruitment process. There are indications that hydrological variables and surface water in particular can explain some of the observed pattern in mortality, but our results indicate that direct human intervention, i.e., charcoal production, is the main cause of tree mortality in the Eastern Desert
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